US2493789A - Production of chromate - Google Patents
Production of chromate Download PDFInfo
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- US2493789A US2493789A US44399A US4439948A US2493789A US 2493789 A US2493789 A US 2493789A US 44399 A US44399 A US 44399A US 4439948 A US4439948 A US 4439948A US 2493789 A US2493789 A US 2493789A
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- United States
- Prior art keywords
- sodium
- chromate
- chloride
- calcium
- bicarbonate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- 238000004519 manufacturing process Methods 0.000 title claims description 47
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 title description 17
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 106
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 96
- BCFSVSISUGYRMF-UHFFFAOYSA-N calcium;dioxido(dioxo)chromium;dihydrate Chemical compound O.O.[Ca+2].[O-][Cr]([O-])(=O)=O BCFSVSISUGYRMF-UHFFFAOYSA-N 0.000 claims description 63
- 239000011780 sodium chloride Substances 0.000 claims description 53
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 51
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 claims description 49
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 claims description 49
- 235000012538 ammonium bicarbonate Nutrition 0.000 claims description 49
- 239000001099 ammonium carbonate Substances 0.000 claims description 49
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims description 48
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 48
- 230000001172 regenerating effect Effects 0.000 claims description 46
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 46
- PXLIDIMHPNPGMH-UHFFFAOYSA-N sodium chromate Chemical compound [Na+].[Na+].[O-][Cr]([O-])(=O)=O PXLIDIMHPNPGMH-UHFFFAOYSA-N 0.000 claims description 37
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 32
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 27
- 239000001110 calcium chloride Substances 0.000 claims description 27
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 27
- 229910021529 ammonia Inorganic materials 0.000 claims description 25
- 229910001948 sodium oxide Inorganic materials 0.000 claims description 25
- 235000019270 ammonium chloride Nutrition 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 24
- KKCBUQHMOMHUOY-UHFFFAOYSA-N sodium oxide Chemical compound [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 claims description 23
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 19
- 230000001590 oxidative effect Effects 0.000 claims description 16
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 15
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 claims description 14
- 239000000920 calcium hydroxide Substances 0.000 claims description 14
- 229910001861 calcium hydroxide Inorganic materials 0.000 claims description 14
- 239000001569 carbon dioxide Substances 0.000 claims description 14
- 239000007788 liquid Substances 0.000 claims description 13
- 229960001407 sodium bicarbonate Drugs 0.000 description 45
- 239000007864 aqueous solution Substances 0.000 description 26
- 229960002713 calcium chloride Drugs 0.000 description 25
- 235000011148 calcium chloride Nutrition 0.000 description 25
- 229960001040 ammonium chloride Drugs 0.000 description 22
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 description 19
- 229910052708 sodium Inorganic materials 0.000 description 19
- 239000011734 sodium Substances 0.000 description 19
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 18
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 14
- 229960005069 calcium Drugs 0.000 description 13
- 239000011575 calcium Substances 0.000 description 13
- 229910052791 calcium Inorganic materials 0.000 description 13
- 235000001465 calcium Nutrition 0.000 description 13
- 238000006243 chemical reaction Methods 0.000 description 13
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 12
- 125000004122 cyclic group Chemical group 0.000 description 12
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 11
- 239000000243 solution Substances 0.000 description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 238000009621 Solvay process Methods 0.000 description 6
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 5
- 239000012267 brine Substances 0.000 description 5
- 229910052804 chromium Inorganic materials 0.000 description 5
- 239000011651 chromium Substances 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 235000017550 sodium carbonate Nutrition 0.000 description 5
- 229910000029 sodium carbonate Inorganic materials 0.000 description 5
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 238000009835 boiling Methods 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- JHWIEAWILPSRMU-UHFFFAOYSA-N 2-methyl-3-pyrimidin-4-ylpropanoic acid Chemical compound OC(=O)C(C)CC1=CC=NC=N1 JHWIEAWILPSRMU-UHFFFAOYSA-N 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- 235000011941 Tilia x europaea Nutrition 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 2
- 239000003085 diluting agent Substances 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 230000008030 elimination Effects 0.000 description 2
- 238000003379 elimination reaction Methods 0.000 description 2
- 239000004571 lime Substances 0.000 description 2
- 239000012452 mother liquor Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- HEUMNKZPHGRBKR-UHFFFAOYSA-N [Na].[Cr] Chemical compound [Na].[Cr] HEUMNKZPHGRBKR-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000001339 alkali metal compounds Chemical class 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 229940117975 chromium trioxide Drugs 0.000 description 1
- GAMDZJFZMJECOS-UHFFFAOYSA-N chromium(6+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Cr+6] GAMDZJFZMJECOS-UHFFFAOYSA-N 0.000 description 1
- 239000013065 commercial product Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000012043 crude product Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- ATADHKWKHYVBTJ-UHFFFAOYSA-N hydron;4-[1-hydroxy-2-(methylamino)ethyl]benzene-1,2-diol;chloride Chemical compound Cl.CNCC(O)C1=CC=C(O)C(O)=C1 ATADHKWKHYVBTJ-UHFFFAOYSA-N 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000036647 reaction Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000002226 simultaneous effect Effects 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 239000012265 solid product Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G37/00—Compounds of chromium
- C01G37/14—Chromates; Bichromates
Definitions
- This invention relates to chromate production and has for an object the provision of an improved process for producing calcium chromate.
- the invention further contemplates the provision of an improved process for recovering chromium in the form of calcium chromate from chromite ore, chromite ore concentrates, altered chromite ore and similar chromium-bearing material's.
- chromite ore is intended to include natural chromite ore, altered chromite ore, chromite ore concentrates and similar chromite mineral-bearing materials.
- chromemite ores are subjected to oxidizing or roasting treatment in the presence of one or more alkali metal compounds suchyfor example, as sodium carbonate, sodium hydroxide and sodium sulphate under such conditions as to oxidize the trivalent chromium of the chromite ores to the hexavalent state and produce alkali meta1 chromates such, for example, as sodium chromate.
- alkali metal compounds suchyfor example, as sodium carbonate, sodium hydroxide and sodium sulphate
- alkali meta1 chromates such, for example, as sodium chromate.
- Sodium chromate thus produced is separated from the product of the roasting or oxidizing treatment by leaching and crystallization and marketed as such or converted to sodium dichromate 'IOI marketing.
- Acomplete preferred process of the invention comprises (:1) reacting sodium chloride and ammonium bicarbonate to produce sodium bi carbonate'and ammonium chloride, (2) regenerating the ammonium bicarbonate by'reacting the ammonium chloride with calcium hydroxide with the production of ammoniaand calcium chloride and by reacting the ammonia thus produced with carbon dioxide in an aqueous liquid
- the production of sodium bicarbonate by reaction of sodium chloride and ammonium bicarbonate preferably includes the step of ammoniation of the, sodium chloride-containing brine,,the step of carbonating the ammoniated brine, and separation of the solid sodium bicarboing the roasting in air of finely divided chromite ore in the presence of available sodium oxide.
- the sodium? oxide may be produced-by employing sodium bicarbonate directly or by employing soda ash produced through decomposition of the sodium bicarbonate.
- the efiect is the same whether:
- sodium bicarbonate or soda ash is employed. The.
- sodium bicarbonate or soda ash is employed in amount suflicient'to provide sodium-oxidefor;
- the chromite ore of thef roasting charge and the charge is heated w a. temperature inthe range '7 50- G. tollOO G.
- the sodium bisolution of sodium chromate may be employedin the calcium-chromate production. step directly, or the solution of sodium chromate may be concentrated or. evaporatedlto dryness to. produce either a concentrated solution or a solid product for use in the calcium chroma-te production step;
- the sodium chromate preferably is added to the calcium chloride-containing solution; which corresponds to the distiller waste solution. of the ammonia soda process, while the solutioncontainsthe heat absorbed in the distillation operation.
- the distiller waste solution also contains the sodium chloride not utilized in the conversion to sodium bicarbonate.
- Thecalcium chloride-containing solution to which the sodium chrom'ate is added preferably isiheated to a. temperature equivalent atleast to: the boiling. temperature at atmospheric. pressure, and it'pref erably is heated to a temperature in: the range,- 126 C.
- the mother liquor may be subjected to an evaporation concentration treatment or not, depending upon the amount of dilution water employed in the process.
- dilution water may be introduced at two points, namely, at the filters as wash water for the' rsodium bicarbonate, and in the distiller in the f orm ofmilk. of lime.
- washing of the sodium bicarbonate at the filters is unnecessary because the crude product can beem'ployed directly in the chromate production step, and, if desired, the lime may be added in; the solid state to the distillers to avoid the introduction of water into the system.
- diluent water may beadded with the sodium chromate, but addition at; this point can be avoided by employing the sodium chromate in the form of a solid. If the addition of diluent water through washing and reagent addition is eliminatedcompletely, it will belnecessaryto add make-up water to compensate .-fo r evaporation. In any event the function;- ingzof the processot the'invention. can be so con.- trolled that evaporation costs will be slight or even negligible. 7
- a cyclic processfcr producing calcium chromate which comprises ('l) reacting sodium chloride and. ammonium bicarbonate to produce sodium bicarbonate and ammonium chloride, ('2). regenerating the ammonium. bicarbonate byre acting the ammonium chloride with calcium hy-'- sity for complete elimination of the chromate fardroxide with the production of ammonia and cal-- cium chloride and by reacting the ammonia thus produced with "carbon dioxide in an. aqueous: liquid, (3) producing calcium chromate and simultaneously regenerating" the sodium chloride by reacting chromic' oxide withthe sodium oxide: of thesodi'um bicarbonate under oxidizing.
- a cyclic process for producing calcium chromate which comprises (1) reacting sodium chloride and ammonium bicarbonate in aqueous solutionto produce sodium bicarbonate and ammonium chloride, (2) regenerating the ammonium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous solution with the production of ammonia and calcium chloride and by reacting the ammonia thus produced with carbon.
- a cyclic process for producing calcium chromate which comprises (1) reacting sodium chloride and ammonium bicarbonate in aqueous solution to produce sodium bicarbonate and ammonium chloride, (2) regenerating the ammo,- nium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous solution with the production of ammonia and calcium chloride and by reacting the ammonia thus produced with carbon dioxide in an aqueous liquid, (3) producing calcium chromate and simultaneously regenerating the sodium chloride by reacting chromic oxide with the sodium oxide of the sodium bicarbonate under oxidizing conditions to form sodium chromate and reacting the sodium chromate with the calcium chloride produced in regenerating the ammonium bicarbonate in aqueous solution under pressure at a temperature above 100 C., (4) separating the calcium chromate from the regenerated sodium chloride and (5) utilizing the regenerated sodium chloride and the regenerated ammonium bicarbonate to regenerate sodium bicarbonate for use in .the
- a cyclic process for producing calcium chro- "mate which comprises (1) reacting sodium chloride and ammonium bicarbonate in aqueous solution to produce sodium bicarbonate 'andfammonium chloride, 2) regenerating the ammonium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous.
- A' cyclic process for producing calcium chromate which comprises (1) reacting sodium chloride and ammonium bicarbonate in aqueous solution to produce sodium bicarbonate and 'ammonium chloride, (2) regenerating, the. ammonium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous solution with the production of ammonia and calcium chloride and by reacting the ammonia thus produced with carbon dioxide in an aqueous liquid; (3) producing calcium chromate and simultaneously regenerating the sodium chloride by reacting chromic oxide with the sodium oxide of the sodium bicarbonate under oxidizing conditions to form sodium chromate and reacting the sodium chromate with the calcium chloride produced in, regenerating the ammonium bicarbonate in aqueous solution under pressure at a temperature in the range 120 C.
- a cyclic process for producing calcium chromate which comprises (1) reacting sodium chloride and ammonium bicarbonate.
- a cyclic process for producing calcium chromate which comprises (1) reacting sodium chlo- 75 ride and vammonium bicarbonatev to: produce produced with carbon dioxide in-anaqueous liquid,
- a cyclic process for producing calcium chromate which comprises -(1) reacting sodium chloride and ammonium bicarbonate aqueous solution to produce sodium bicarbonate and am- 'monium chloride, (2) regenerating the am- -monium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous'solution with the production of ammonia and cal- :zcium chloride and :by reacting the .ammonia thus produced with carbon dioxide in an aqueous (39 producing calcium r-c'hromate and is'i- :multaneously regenerating the sodium :chloridez:
- a cyclic process for producing ecalcium rchromate which comprises (1) reactingrsodium .-chloride and ammonium .ibicarhonateo'in aqueous solution "to produce :sodium bicarbonate and amjmonium chloride, (2) regenerating the 1am- -monium bicarbonate: by reacting the :ammonium chloride with calcium hydroxide aqueous-solu- 'tion with 'the/ productionliqf ammonia and cal- :cium chloride and vby reactingiithe: ammonia ithus zproduced with carbon dioxide in van aqueous diquid, (-3) producing calcium "chromate' zmd .s'i
- a cyclic process :iior producing calcium chromate which comprises (1') reacting sodium chloride and U ammonium -bicarbonate in-aqueous solution to produce sodium-bicarbonate and-amvmoniumrchloride, (2) regenerating the-ammonium bicarbonateibyreacting the ammonium chloride with calcium hydroxide in-a'queous solution "with :the production of ammonia and calcium --c'hloride I anduby reacting the ammonia thus pro prised with carbon dioxide in an aqueous liquid, ('3) producing calcium chrom-ate and simultan fl-eously regenerating the sodium chloride' byreacting chromic oxide with-the-sodiumoxide cf the sodium bicarbonate under oxidizing conditions tc-form sodium chromaterand reacting the sodium chromate with the calcium chloride produced in regenerating the ammonium bicarbonate in aqueous solution under pressure above "15 pounds :per
- a cyclic process for producing calcium chromate which comprises (-1) reacting sodium chloride and ammonium-'bicaflaonate in aqueous solution to produce sodium bicarbonate and animonium chloride, (2) regenerating the fammonium bicarbonate by reacting'tjhe ammonium chloride with calcium hydroxide in aqueous solution with the -production of ammonia and calcium 7 (3) producing calcium chromate and simultaneously regenerating the sodium chloride by reacting chromic oxide with the sodium oxide of the sodium bicarbonate under oxidizing conditions to form sodium chromate and reacting the sodium chromate with the calcium chloride produced in regenerating the ammonium bicarbonate in aqueous solution under pressure at a temperature in the range 120 C.
- a cyclic process for producing calcium chromate which comprises (1) reacting sodium chloride and ammonium bicarbonate in aqueous solution to produce sodium bicarbonate and ammonium chloride, (2) regenerating the ammonium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous solution with the production of ammonia and calcium chloride and by reacting the ammonia thus produced with carbon dioxide in an aqueous liquid, (3) producing calcium chromate and simultaneously regenerating the sodium chloride by reacting chromic oxide with the sodium oxide of the sodium bicarbonate under oxidizing conditions to 10 form sodium chromate and reacting the sodium chromate with the calcium chloride produced in regenerating the ammonium bicarbonate in aqueous solution under pressure in the range, 15 to 30 pounds per square inch, at a temperature in the range, C.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Description
Patented Jan. 10, 1950' UNITED STATES PATENTTOFFICE 2,493,789. I 1 I PRODUCTION OF CHROMATE Marvin J. Udy, Nia ara Fal1s, N ;Y; No Drawing. Application'August 14,V194s,
Serial No. 44 399;
14 Claims. (Cl. 23-56)' This invention relates to chromate production and has for an object the provision of an improved process for producing calcium chromate. The invention further contemplates the provision of an improved process for recovering chromium in the form of calcium chromate from chromite ore, chromite ore concentrates, altered chromite ore and similar chromium-bearing material's.
Throughout the specification and in the claims, the term chromite ore is intended to include natural chromite ore, altered chromite ore, chromite ore concentrates and similar chromite mineral-bearing materials.
According to some heretofore customary practices,"chromite ores are subjected to oxidizing or roasting treatment in the presence of one or more alkali metal compounds suchyfor example, as sodium carbonate, sodium hydroxide and sodium sulphate under such conditions as to oxidize the trivalent chromium of the chromite ores to the hexavalent state and produce alkali meta1 chromates such, for example, as sodium chromate. Sodium chromate thus produced is separated from the product of the roasting or oxidizing treatment by leaching and crystallization and marketed as such or converted to sodium dichromate 'IOI marketing. Commercial sodium chromate and sodium dichromate are utilized as raw or intermediate materials in the production of other chromium-bearing compounds, including calcium chromate. Usually, the calcium chromate production operations are carried out independently of the sodium chromate production operations and, consequently, the sodium oxide content of the sodium chromate is wasted or, at any rate, is not recovered in a form in which it is readily available for re-use in the chromate production operations. For this reason, among others, calcium chromate is a relatively costly commercial product. Calcium chromate is a highly desirable material for many industrial uses, but its usefulness has not been developed fully because of its high cost.
The present invention provides for the production of calcium chromate under conditions and according to procedures such that the sodium oxide content of sodium chromate employed in its production is utilized for the production of addi- The-two procedures arecombined with advantage they may-be represented by the following equations for purposes of illustration:
(1) 4NaCl+ LNH4I-ICO =4NaHCOs+4NH4Cl 2) CI'2O3+4N aI-ICO3+1 O2= j v 2Na2 CrQ4+2I-I2CO3+2 CO2 (3) 2NaaCrO4-i 2CaClz:2CaCrO4+4NaCl on znmc g zca(on) =4mn+ zoacn+ imo The 'foregoin'gequations illustrate the principal reactions.- The -following'equations illustrate additional reactions involvedin the process Acomplete preferred process of the invention comprises (:1) reacting sodium chloride and ammonium bicarbonate to produce sodium bi carbonate'and ammonium chloride, (2) regenerating the ammonium bicarbonate by'reacting the ammonium chloride with calcium hydroxide with the production of ammoniaand calcium chloride and by reacting the ammonia thus produced with carbon dioxide in an aqueous liquid, (3) producing "calcium chromate and simultaneously regenerating the sodium chloride by reacting chromic oxide with'the sodium'oxide of the sodium bi carbonate under oxidizing conditions to form sodium chromate and reacting the sodium chromate with thecalcium chloride produced in regenerating the ammonium bicarbonate, (4) separating the calcium chromate from the regenerated sodium chloride, and (5) utilizing the regenerated sodium chloride and the regenerated ammonium bicarbonate to regenerate sodium bicarbonate for use in the production of additional calcium chromate. I
-As in the operation of the ammonia soda process to produce sodium bicarbonate as an end product; the production of sodium bicarbonate by reaction of sodium chloride and ammonium bicarbonate preferably includes the step of ammoniation of the, sodium chloride-containing brine,,the step of carbonating the ammoniated brine, and separation of the solid sodium bicarboing the roasting in air of finely divided chromite ore in the presence of available sodium oxide. The sodium? oxide may be produced-by employing sodium bicarbonate directly or by employing soda ash produced through decomposition of the sodium bicarbonate. The efiect is the same whether:
sodium bicarbonate or soda ash is employed.. The.
sodium bicarbonate or soda ash is employed in amount suflicient'to provide sodium-oxidefor;v
combining with all of the chromium of the chromite ore when converted to the hexavalentstate" The sodium bicarto form chromium trioxide.
bonate or the soda ash is mixed intimately with;
the chromite ore of thef roasting charge, and the charge is heated w a. temperature inthe range '7 50- G. tollOO G. In the course of: the heating operation in the presence of.-air,. the sodium bisolution of sodium chromate" may be employedin the calcium-chromate production. step directly, or the solution of sodium chromate may be concentrated or. evaporatedlto dryness to. produce either a concentrated solution or a solid product for use in the calcium chroma-te production step;
The sodium chromate preferably is added to the calcium chloride-containing solution; which corresponds to the distiller waste solution. of the ammonia soda process, while the solutioncontainsthe heat absorbed in the distillation operation. Incidentally, the distiller waste solution also contains the sodium chloride not utilized in the conversion to sodium bicarbonate. Thecalcium chloride-containing solution to which the sodium chrom'ate is added preferably isiheated to a. temperature equivalent atleast to: the boiling. temperature at atmospheric. pressure, and it'pref erably is heated to a temperature in: the range,- 126 C. to 135 C., under a pressure; in the range, 15 to 30 pounds per square inch, toeffect precipitation of anhydrous calcium chromate At temperatures and pressures in the ranges indicated, precipitationv of. calcium chromatevirtual ly is complete. Complete removalof the calcium; chromate is notessential to the economy of the process, as the mother liquor from the precipitation treatment is to be ire-cycled to regenerate sodium. bicarbonate, and chromate remaining therein will not interfere with the reactions involved in the ammonia soda process. The chromate will remain in the system without loss. When equilibrium has been established, calcium-. chromate equivalent to the sodium chromateem- 7 ployed will be obtained at aiuniformrate. The":
advantage resulting from avoidance of the neces- The mother liquor may be subjected to an evaporation concentration treatment or not, depending upon the amount of dilution water employed in the process. In the ammonia soda process designed and operated for the production of a sodium bicarbonate product for marketing as such, dilution water may be introduced at two points, namely, at the filters as wash water for the' rsodium bicarbonate, and in the distiller in the f orm ofmilk. of lime. In the process of the invention, washing of the sodium bicarbonate at the filters is unnecessary because the crude product can beem'ployed directly in the chromate production step, and, if desired, the lime may be added in; the solid state to the distillers to avoid the introduction of water into the system. In
j the'process of the invention, diluent water may beadded with the sodium chromate, but addition at; this point can be avoided by employing the sodium chromate in the form of a solid. If the addition of diluent water through washing and reagent addition is eliminatedcompletely, it will belnecessaryto add make-up water to compensate .-fo r evaporation. In any event the function;- ingzof the processot the'invention. can be so con.- trolled that evaporation costs will be slight or even negligible. 7
The combined usev ot-the principles and reactionsof the ammoniasoda process and the principles-and reactions of a. calcium chromate-product-ion process permits the achievement of the fol-lowing advantages, among others:
(1) It permits re-use of the brine with a: saving in. cost of raw materials, a saving in the cost' of preparing and; purifying the brine and with; the establishment of more uniform conditions leading to greater .efliciency through the use of brine ofi the-sameacomposition in all, am'moniation and carbonation operations." l
1(2) Itperm'its the-saving and utilization: in the production of the endiproduct of the combined process .of calcium chloride which normally is wasted in the: ammonia sodaprocess.
p (3); It conserves the heat of the distiller waste solution which normally is dissipated without ac complishinga useful; result or is used inefficiently, and, itpermits utilization of the heat directly in:
the production of theend'product of: the combined:
process.
- 4) It permitsa saving in labor and. equipment:
7 costs by permitting elimination of. washing ofthe sodium bicarbonate at the. filters.
..I claim: 1 1 :1- A cyclic processfcr producing calcium chromate which comprises ('l) reacting sodium chloride and. ammonium bicarbonate to produce sodium bicarbonate and ammonium chloride, ('2). regenerating the ammonium. bicarbonate byre acting the ammonium chloride with calcium hy-'- sity for complete elimination of the chromate fardroxide with the production of ammonia and cal-- cium chloride and by reacting the ammonia thus produced with "carbon dioxide in an. aqueous: liquid, (3) producing calcium chromate and simultaneously regenerating" the sodium chloride by reacting chromic' oxide withthe sodium oxide: of thesodi'um bicarbonate under oxidizing. con ditions, to formsodium chromate and reacting the-sodiumchromate with: the calcium chloride produced in regenerating theiammonium bicarbonate, (4') separating the calcium chromate ate-sodium bicarbonate for use in the productionof v additional calcium chromate.
monium chloride, (2) regenerating the ammonium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous solution with the production ofammonia and calcium chloride and by reacting theammonia thus produced with carbon dioxide in an aqueous liquid, f
(3) producing calcium chromate and simultaneously regenerating the sodium chloride by re: .acting chromic oxide with the; sodium oxide of the. sodium bicarbonate underoxidizing conditions to form sodium chromate and reacting the r sodium chromate with-the calcium chloride produced in regenerating the ammonium bicarbonate at an elevated temperature, (4) separating the calcium chromate from the regenerated sodium chloride, and utilizing the regener ated sodium chloride and the regenerated ammonium bicarbonate to regenerate sodium bicarbonate for use in the production of additional calcium chromate.
3. A cyclic process for producing calcium chromate which comprises (1) reacting sodium chloride and ammonium bicarbonate in aqueous solutionto produce sodium bicarbonate and ammonium chloride, (2) regenerating the ammonium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous solution with the production of ammonia and calcium chloride and by reacting the ammonia thus produced with carbon. dioxide in an 1 aqueous liquid, (3) producing calcium chromateand simultaneously regenerating the sodium chloride by reacting chromic oxide with the sodium oxide ofthe sodium bicarbonate under oxidizing conditions to form sodium chromate and reacting the sodium chromate with the calcium chloride produced in regenerating the ammonium bicarbonate in aqueous solution at a boiling temperature, (4) separating the calcium chromate from the regenerated sodium chloride, and (5) .utilizing the regenerated sodium chloride and the regenerated ammonium bicarbonate to regenerate sodium bicarbonate for use in the production of additional. calcium chromate.
.. 4. A cyclic process for producing calcium chromate which comprises (1) reacting sodium chloride and ammonium bicarbonate in aqueous solution to produce sodium bicarbonate and ammonium chloride, (2) regenerating the ammo,- nium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous solution with the production of ammonia and calcium chloride and by reacting the ammonia thus produced with carbon dioxide in an aqueous liquid, (3) producing calcium chromate and simultaneously regenerating the sodium chloride by reacting chromic oxide with the sodium oxide of the sodium bicarbonate under oxidizing conditions to form sodium chromate and reacting the sodium chromate with the calcium chloride produced in regenerating the ammonium bicarbonate in aqueous solution under pressure at a temperature above 100 C., (4) separating the calcium chromate from the regenerated sodium chloride and (5) utilizing the regenerated sodium chloride and the regenerated ammonium bicarbonate to regenerate sodium bicarbonate for use in .the production of additional calcium chromate. 5. A cyclic process for producing calcium chro- "mate which comprises (1) reacting sodium chloride and ammonium bicarbonate in aqueous solution to produce sodium bicarbonate 'andfammonium chloride, 2) regenerating the ammonium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous. solution withthe production of ammonia and calcium chloride and by reacting the ammonia thus produced with 'carbon dioxide in an 5 aqueous liquid, (3) producing calcium chromate and simultaneousiy regenerating the sodium chloride by reacting chromic oxide with the sodium oxide of, the sodium bicarbonate under oxidizing con- .ditions toform sodium chromate and reacting the sodium chromate with the calcium chloride produced in regenerating the ammonium bicarbonate in, aqueous solution under pressure above pounds per square inch atra temperature above 120 C., (4) separating the calcium chromate .from the regenerated sodium chloride and (5) utilizing the regenerated sodium chloride and the regenerated ammonium bicarbonate to regenerate-sodium bicarbonate for use inthe production of additional calcium chromate. I 6. A' cyclic process for producing calcium chromate which comprises (1) reacting sodium chloride and ammonium bicarbonate in aqueous solution to produce sodium bicarbonate and 'ammonium chloride, (2) regenerating, the. ammonium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous solution with the production of ammonia and calcium chloride and by reacting the ammonia thus produced with carbon dioxide in an aqueous liquid; (3) producing calcium chromate and simultaneously regenerating the sodium chloride by reacting chromic oxide with the sodium oxide of the sodium bicarbonate under oxidizing conditions to form sodium chromate and reacting the sodium chromate with the calcium chloride produced in, regenerating the ammonium bicarbonate in aqueous solution under pressure at a temperature in the range 120 C. to 135 C., (4) separating the calcium chromate from the vroegenerated sodium chloride and (5) utilizing the regeneratedsodium chloride and the regenerated ammonium bicarbonate to regenerate sodium bicarbonate for use in the production of additional calcium chromate. V '7. A cyclic process for producing calcium chromate which comprises (1) reacting sodium chloride and ammonium bicarbonate. in aqueous solution to produce sodium bicarbonate and ammonium chloride, (2) regenerating the ammonium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous solution with the production .of ammonia and calcium chloride and by reacting the ammonia thus produced with carbon dioxide in an aqueous liquid, .(3) producing calcium chromate and simultaneously regenerating the sodium chloride by reacting chromic oxide with the sodium oxide of the sodium bicarbonate under oxidizing conditions to form sodium chromate and reacting the sodium chromate with the calcium chloride produced in regenerating the ammonium bicarbonate in aqueous solution under pressure in the range 15 to pounds per square inch, at a temperature in the range, 120 C. to 135 C., (4) separating the calcium chromate from the regenerated sodium chloride and (5) utilizing the regenerated sodium chloride and the regenerated ammonium bicarbonate to regenerate sodium bicarbonate forum in the production of additional calcium chromate.
-8.1 A cyclic process for producing calcium chromate which comprises (1) reacting sodium chlo- 75 ride and vammonium bicarbonatev to: produce produced with carbon dioxide in-anaqueous liquid,
K39 producing calcium :chromate and simultaneousl-yregenerating thesodi-umchioride byreacting chromic oxide with t-he sodium oxide of the sodium bicarbonate under oxidizing conditions to form sodium chromate and reacting the sodium zchromate with the calcium chloride produced'in regenerating the ammonium bicarbonate, (4)
p separating the calcium .chromate from the rogramerated sodium chloridaand (5-) utilizing the regenerated sodium chloride and the regenerated ammonium bicarbonate to regenerate sodium bicarbonate for use in the production of additional calcium chromate, the reaction between the chromic (oxide and thezsodium oxide of the bicarbonate being effected-by roasting'a mixture comprising chromite ore andthe sodium oxide in air at a temperaturein the range 750 0.1130 1100' C.
9. A cyclic process for producing calcium chromate which comprises -(1) reacting sodium chloride and ammonium bicarbonate aqueous solution to produce sodium bicarbonate and am- 'monium chloride, (2) regenerating the am- -monium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous'solution with the production of ammonia and cal- :zcium chloride and :by reacting the .ammonia thus produced with carbon dioxide in an aqueous (39 producing calcium r-c'hromate and is'i- :multaneously regenerating the sodium :chloridez:
by reacting .chromic oxide with-the'sodiumnoxide f thesodium.-1: icarbonate underoxidizing conditions to form sodium .chromate and reacting --the sodium chromate with the'calcium chloride produced in regenerating the ammonium bicarbonate at an elevated temperature, 14') -separating the calcium chromate from the regeneraated sodium chloride, and utilizing the regenmated sodium chloride and i the regenerated am- -monium bicarbonate Ito regenerate .sodiumxbicarbonate :ior use in the production of additional calcium chromate, the reaction between the chromic ioxide and the sodiunimrid'elzof the bi- -carbonate .zbeing effected by :roasting :a mhdtmie comprising chromite :ore and the :sodiummrdde 1 "in air at a temperature "in :the range 3750 Cr-lto 1160:C.. A i
.10. A cyclic process for producing ecalcium rchromate which comprises (1) reactingrsodium .-chloride and ammonium .ibicarhonateo'in aqueous solution "to produce :sodium bicarbonate and amjmonium chloride, (2) regenerating the 1am- -monium bicarbonate: by reacting the :ammonium chloride with calcium hydroxide aqueous-solu- 'tion with 'the/ productionliqf ammonia and cal- :cium chloride and vby reactingiithe: ammonia ithus zproduced with carbon dioxide in van aqueous diquid, (-3) producing calcium "chromate' zmd .s'i
multaneously regenerating the sodiumichzluridezfiby reacting chromic oxide WithJ-the sodium aOXi'dB of the sodium bicarbonate .under oxidizing conditions :to form. sodium chromate and reactingthe sodium chromate' with the calcium chloride prosduced .in regenerating theammonium bicarbonate --in ;a'queous solution ate-a z-boiling temperature, (4. separating the calcium chromate'from the regen .erated sodium chloride. and (5) utilizing git-he regenerated sodium chloride the z regenerateii ammonium rsbicarbonate m) regenerate bicarbonate ioriuse in f the production of "additional calcium chromate, the react-ion between the chromic oxide and the sodium oxide oi the bicarbonate being effected by reacting a mixchromate which comprises (1) reacting sodium "chloride and ammonium bicarbonate in aqueous SOlll-i'ilOll to produce sodium bicar'bona te and ammonium -chloride, (2-) regenerating the ammonium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous-solution with the production of ammOnia-and'caIGium chloride and by reacting the ammonia thus produced with carbon dioxide in an aqueous liquid, (-3) producing calcium chromate and simultaneou'sly regenerating the sodiumch l'oride by reacting chromic oxide with the-sodium "oxide of :the sodium bicarbonate under oxidizing conditions to form sodium chromate and reacting the sodium 'chromate with the calcium chloride produced regenerating the ammonium bicarbonate in aqueous solution under pressure at a temperature above 13., i4) separating the calcium chromate from the regenerated sodium chloride and (5) utilizing the regeneratedsodiumchloride-arid the regenerated ammonium bicarbonate to regen- --er.ate sodium bicarbonate for use inthe production of additional calcium chromate, the reaction between the chromic .oxide and the-sodium oxide "of the bicarbonate being eiiected -by roasting a mixture comprisingchromite ore-and the sodium oxide in air at a temperature in the range'fl50 0. 1201100 0. V r .112 A cyclic process :iior producing calcium chromate which comprises (1') reacting sodium chloride and U ammonium -bicarbonate in-aqueous solution to produce sodium-bicarbonate and-amvmoniumrchloride, (2) regenerating the-ammonium bicarbonateibyreacting the ammonium chloride with calcium hydroxide in-a'queous solution "with :the production of ammonia and calcium --c'hloride I anduby reacting the ammonia thus pro duced with carbon dioxide in an aqueous liquid, ('3) producing calcium chrom-ate and simultan fl-eously regenerating the sodium chloride' byreacting chromic oxide with-the-sodiumoxide cf the sodium bicarbonate under oxidizing conditions tc-form sodium chromaterand reacting the sodium chromate with the calcium chloride produced in regenerating the ammonium bicarbonate in aqueous solution under pressure above "15 pounds :per square inch at a temperature above 0;, (4) separating the calcium chromate from the regenerated sodium 'chlorideand (5-) utilizing the regenerated sodium chloride and the regenerated ammonium bicarbonate to regenerate so- -dium bicarbonate ioruse in the production of additional calcium chromate, --=the reaction between the chromic' oxide and the sodium-oxide of the bicarbonate being eliected by roasting a mixture comprising chromite ore and the sodium oxide in air at a temperature in the range750C. to 1100 C. r A cyclic process for producing calcium chromate which comprises (-1) reacting sodium chloride and ammonium-'bicaflaonate in aqueous solution to produce sodium bicarbonate and animonium chloride, (2) regenerating the fammonium bicarbonate by reacting'tjhe ammonium chloride with calcium hydroxide in aqueous solution with the -production of ammonia and calcium 7 (3) producing calcium chromate and simultaneously regenerating the sodium chloride by reacting chromic oxide with the sodium oxide of the sodium bicarbonate under oxidizing conditions to form sodium chromate and reacting the sodium chromate with the calcium chloride produced in regenerating the ammonium bicarbonate in aqueous solution under pressure at a temperature in the range 120 C. to 135 C., (4) separating the calcium chromate from the regenerated sodium chloride and utilizing the regenerated sodium chloride and the regenerated ammonium bicarbonate to regenerate sodium bicarbonate for use in the production of additional calcium chromate, the reaction between the chromic oxide and the sodium oxide of the bicarbonate being efiected by roasting a mixture comprising chromite ore and the sodium oxide in air at a temperature in the range 750 C. to 1100 C.
14. A cyclic process for producing calcium chromate which comprises (1) reacting sodium chloride and ammonium bicarbonate in aqueous solution to produce sodium bicarbonate and ammonium chloride, (2) regenerating the ammonium bicarbonate by reacting the ammonium chloride with calcium hydroxide in aqueous solution with the production of ammonia and calcium chloride and by reacting the ammonia thus produced with carbon dioxide in an aqueous liquid, (3) producing calcium chromate and simultaneously regenerating the sodium chloride by reacting chromic oxide with the sodium oxide of the sodium bicarbonate under oxidizing conditions to 10 form sodium chromate and reacting the sodium chromate with the calcium chloride produced in regenerating the ammonium bicarbonate in aqueous solution under pressure in the range, 15 to 30 pounds per square inch, at a temperature in the range, C. to C., (4) separating the calcium chromate from the regenerated sodium chloride and (5) utilizing the regenerated sodium chloride and the regenerated ammonium bicarbonate to regenerate sodium bicarbonate for use in the production of additional calcium chromate, the reaction between the chromic oxide and the sodium oxide of the bicarbonate being efiected by roasting a mixture comprising chromite ore and the sodium oxide in air at a temperature in the range 750 C. to 1100 C.
MARVIN J. UDY.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS facture of Soda, (1933)
Claims (1)
1. A CYCLIC PROCESS FOR PRODUCING CALCIUM CHROMATE WHICH COMPRISES (1) REACTING SODIUM CHLORIDE AND AMMONIUM BICARBONATE TO PRODUCE SODIUM BICARBONATE AND AMMONIUM CHLORIDE, (2) REGENERATING THE AMMONIUM BICARBONATE BY REACTING THE AMMONIUM CHLORIDE WITH CALCIUM HYDROXIDE WITH THE PRODUCTION OF AMMONIA AND CALCIUM CHLORIDE AND BY REACTING THE AMMONIA THUS PRODUCED WITH CARBON DIOXIDE IN AN AQUEOUS LIQUID, (3) PRODUCING CALCIUM CHROMATE AND SIMULTANEOUSLY REGENERATING THE SODIUM CHLORIDE BY REACTING CHROMIC OXIDE WITH THE SODIUM OXIDE OF THE SODIUM BICARBONATE UNDER OXIDIZING CONDITIONS TO FORM SODIUM CHROMATE AND REACTING THE SODIUM CHROMATE WITH THE CALCIUM CHLORIDE PRODUCED IN REGENERATING THE AMMONIUM BICARBONATE, (4) SEPARATING THE CALCIUM CHROMATE FROM THE REGENERATED SODIUM CHLORIDE, AND (5) UTILIZING THE REGENERATED SODIUM CHLORIDE AND THE REGENERATED AMMONIUM BICARBONATE TO REGENERATE SODIUM BICARBONATE FOR USE IN THE PRODUCTION OF ADDITIONAL CALCIUM CHROMATE.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US44399A US2493789A (en) | 1948-08-14 | 1948-08-14 | Production of chromate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US44399A US2493789A (en) | 1948-08-14 | 1948-08-14 | Production of chromate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2493789A true US2493789A (en) | 1950-01-10 |
Family
ID=21932173
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US44399A Expired - Lifetime US2493789A (en) | 1948-08-14 | 1948-08-14 | Production of chromate |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2493789A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2745765A (en) * | 1953-03-04 | 1956-05-15 | Vanadium Corp Of America | Process of precipitating substantially anhydrous calcium chromate and product resulting therefrom |
| US2745715A (en) * | 1953-03-04 | 1956-05-15 | Vanadium Corp Of America | Process of precipitating substantially anhydrous calcium chromate |
| US2745764A (en) * | 1953-03-04 | 1956-05-15 | Vanadium Corp Of America | Process of precipitating substantially anhydrous calcium chromate and product resulting therefrom |
| US4171248A (en) * | 1977-11-03 | 1979-10-16 | Ppg Industries, Inc. | Method of opening chrome ore |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US200134A (en) * | 1878-02-12 | Improvement in processes for utilizing zinc sulphate | ||
| US1955326A (en) * | 1930-05-09 | 1934-04-17 | Bozel Maletra Prod Chimiques | Process for the manufacture of chromates and dichromates |
| US2402103A (en) * | 1942-03-19 | 1946-06-11 | Marvin J Udy | Production of chromium compounds |
-
1948
- 1948-08-14 US US44399A patent/US2493789A/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US200134A (en) * | 1878-02-12 | Improvement in processes for utilizing zinc sulphate | ||
| US1955326A (en) * | 1930-05-09 | 1934-04-17 | Bozel Maletra Prod Chimiques | Process for the manufacture of chromates and dichromates |
| US2402103A (en) * | 1942-03-19 | 1946-06-11 | Marvin J Udy | Production of chromium compounds |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2745765A (en) * | 1953-03-04 | 1956-05-15 | Vanadium Corp Of America | Process of precipitating substantially anhydrous calcium chromate and product resulting therefrom |
| US2745715A (en) * | 1953-03-04 | 1956-05-15 | Vanadium Corp Of America | Process of precipitating substantially anhydrous calcium chromate |
| US2745764A (en) * | 1953-03-04 | 1956-05-15 | Vanadium Corp Of America | Process of precipitating substantially anhydrous calcium chromate and product resulting therefrom |
| US4171248A (en) * | 1977-11-03 | 1979-10-16 | Ppg Industries, Inc. | Method of opening chrome ore |
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